GIGABYTE HD7790 Review

Sub £100 graphics cards are rare, especially when gaming at 1080p. Today, we get to sample AMD’s HD7790 courtesy of GIGABYTE to see if it has what it takes…

Product on Review: GIGABYTE HD7790
Manufacturer and Sponsor: GIGABYTE
Street Price: £98

The AMD Radeon HD 7790, codenamed ‘Bonaire’, is the latest entry level graphics card to exit the AMD laboratories. We tested the HD7750 and 7770 some time ago now but with NVIDIA’s GTX650Ti stealing the limelight recently, AMD have upped the ante by releasing this GPU with an entirely new 28nm Graphics Core Next ASIC and in doing so hope to reclaim the entry level crown. We get a first glance of the card today before committing ourselves to our usual full in-depth review.

Entry level gaming now demands a card capable of performing at today’s most popular resolution of 1920x1080p (according to Steam). The HD7750 and HD7770 just about managed this but was found wanting in some areas, typically struggling to reach a minimum playable frame rate at this high resolution, especially when filtering was required. The HD7790 hopes to rectify this with an increase in computational power and memory clockspeeds without sacrificing the appeal of a low power draw.

The AMD HD7790 is not however a replacement of the HD7770, it is a totally new design aimed squarely at the NVIDIA GTX650Ti. AMD are confident there efforts will see there HD7790 design beat the GTX650Ti into submission. We just so happen to have the GTX650Ti and the GTX660 along with the HD7790’s brethren so it will be interesting to see where the new GPU gains a foothold. Before we take a look at the card itself, let’s examine the specifications a little more closely…

GIGABYTE: Leader in IT Innovation

GIGABYTE was founded in 1986, establishing our uncontested position in continuous technological innovation. By focusing on key technologies and achieving strict quality standards, GIGABYTE has been regarded as an innovative and trusted motherboard leader in the globe. To keep pace in a rapidly changing world, we have offered a comprehensive product line covering Motherboards, Graphics Cards, PC Components, PC Peripherals, Laptops, Slate Devices, Desktop PCs, Network Communications, Servers and Mobile Phones. We are dedicated to building up a full-range digital life, responding promptly and sonorously to consumer needs and desires.

Specification

The table below shows an ‘apples to apples’ comparison between the HD7750, HD7770 and HD7790 graphics cards currently available from AMD:

The new core compares favourably against it’s siblings by having a 25% increase in transistor count over both the HD7750 and HD7770 along with a 256 increase in stream processors over the HD7770. The result is a near 40% increase in compute performance (1.28 TFLOPS vs 1.78 TFLOPS). Memory clockspeed also sees a boost from 4.5Gbps to 6Gbps. All of this extra power will only cost you an extra 5w with the HD7790 typically consuming just 85W.

On paper at least there have been some significant improvements not least with the price which for all the enhancements this card provides, AMD expects its board partners to retail the card at a touch under £100 mark, matching the current price of the HD7770 so expect to see some cuts to the lower end of the family.

The AMD HD7790 continues to be based upon the GCN (Graphics Core Next) architecture which in this case comprises of twin geometry and tessellation engines. The 14 GCN units make up a count of 896 Stream Processors with 16 render output units.

Another improvement is a 100% increase in the levels of DPM from 4 to 8. The 8 clock/voltage DPM pairings allow for higher engine clock speeds while maintaining optimum voltage levels.

Let’s move on to the features of the HD7790…

Features

AMD CrossFire™ Technology
The AMD Radeon™ HD 7700 GPU supports AMD CrossFire™ Technology and provides excellent multi GPU scaling. With the introduction of the AMD Radeon™ HD 6900 Series Graphics, AMD began delivering improved AMD CrossFire™ Technology scaling when using two GPUs. AMD is proud to continue to offer that amazing performance with its newest AMD Radeon™ HD 7000 series graphics products.

AMD Eyefinity Technology
AMD Eyefinity Technology provides advanced multiple monitor technology enabling an incredibly immersive graphic and computing experience with innovative display capabilities, supporting massive desktop workspaces and super-high resolution gaming environments. AMD Eyefinity technology with DisplayPort connectivity enables a single GPU to support up to six independent display outputs simultaneously, depending on the OEM implementation.
AMD Eyefinity technology works with games that support non-standard aspect ratios, which is required for panning across multiple displays. To enable more than two displays, one of two cases must be satisfied:

1) Additional panels with native DisplayPort™ connectors are used;
2) Certified DisplayPort™ adapters to convert your monitor’s native input to your cards

DisplayPort™ or Mini-DisplayPort™ connector(s) are used.
With the introduction and wide availability of DisplayPort™ to single-link DVI dongles, option 2 above is a low cost way to convert a set of already-owned monitors into an AMD Eyefinity technology ready display configuration.

Unlike a similar multi monitor gaming solution offered by NVIDIA, AMD Eyefinity technology does not require two graphics cards to work. Therefore, AMD offers a multi monitor gaming solution with potential for a lower setup cost.

Improved Tessellation
The latest iteration of architecture in the AMD Radeon™ HD 7770 GPU features a brand new Generation of Tesselator (Gen 9) in its Geometry Engine. This features optimizations such as; Increased vertex re-use, Off-chip buffering improvements and larger parameter caches. This helps Improve performance at all tessellation factors at up to 4x the throughput of AMD Radeon™ HD 6900 series graphics (Gen 8 ).

AMD HD3D Technology
AMD HD3D Technology is supported by an advanced and open ecosystem that, in conjunction with specific AMD hardware and software technologies, enables 3D display capabilities for many PC applications and experiences.

Your PC has evolved, offering unprecedented amount of games, photos and movies for you to play, watch, design, create, share and download in 3D. With the arrival of the latest in 3D technology you can now enjoy an enhanced visual experience on Stereo 3D-capable desktops and notebooks powered by AMD HD3D Technology.

HDMI 1.4a
More bandwith than standard HDMI allows full implementation of 60Hz Stereo 3D. Standard HDMI ports do not have adequate bandwidth for more than 3D 1080p at 24fps.

Ultra-high resolution (4k Panels)
– Current implementations currently use 4*DVI or 2*DP 1.1, which is expensive and unwieldy.
– AMD will move to a single-connector output for 4k via DP 1.2 HBR2 and HDMI 1.4a 3GHz mode.

AMD Quad Buffer SDK
– Native 3D support for Developers.
– functions with Dx9, 10 and 11
– Native support scheduled for Windows 8
Nearly 600 games support AMD’s implementation of 3D either natively or through middleware partners. Also support for many 3D displays already on the market including Samsung and LG’s proprietry implementation.

AMD Zerocore Power

When a discrete GPU is in a static screen state it works to minimize idle power by enabling a host of active power saving functions including (but not limited to); clock gating, power gating, memory compression, and a host of other features. However, GPUs with AMD’s exclusive ZeroCore Power technology can take energy savings to entirely new heights by completely powering down the core GPU while the rest of the system remains active.

Nearly all PCs can be configured to turn off their displays after a long period of inactivity. This is known as the long idle state; where the screen is blanked but the rest of the system remains in an active and working power state (ACPI G0/S0). As soon as the system goes into long idle state and applications are not actively changing the screen contents, the GPU enters the ZeroCore power state. In the ZeroCore power state, the GPU core (including the 3D engine / compute units, multimedia and audio engines, displays, memory interfaces, etc.) is completely powered down.

However, one cannot simply remove the GPU and its associated device context completely; particularly when it is the only GPU in the system as is the case in many enthusiast platforms. The operating system and SBIOS must still be aware that a GPU is still present in the system. For this reason, the ZeroCore Power state maintains a very small bus control block to ensure that GPU context is still visible to the operating system and SBIOS. The ZeroCore power state also manages the power sequencing of the GPU to ensure that the power up/down mechanism is self-contained and independent of the rest of the system.

The enablement of the ZeroCore Power feature is controlled by the driver. The driver monitors the display contents and allows the GPU to enter the ZeroCore Power in the condition that the GPU enters long idle and subsequent work requests are no longer being submitted to the engine. If any applications update the screen contents, ZeroCore Power technology can periodically wake the GPU to update the framebuffer contents and put the GPU back into the ZeroCore Power state. Furthermore, applications such as Windows 7 desktop gadgets are architected to minimize activity and save power in the long idle state. These applications are active during screen-on mode to display dynamic content such as weather, RSS feeds, stock symbols, system status, etc. but also have the intelligence to suspend any updates and activity when the system enters long idle. These applications will not wake the GPU from the ZeroCore Power state in long idle.

AMD ZeroCore Power technology delivers tremendous energy savings. Many PCs remain in the long idle state for a variety of use cases that are highly relevant to everyday consumers, enthusiasts and professionals. In ZeroCore Power mode, users can still enjoy non-graphics activities such as file serving/streaming, motherboard audio and music, and remote access while the GPU core is essentially powered off.

ZeroCore Power technology also scales with AMD CrossFire™ technology. With an AMD CrossFire platform, all non-primary GPUs are in the ZeroCore Power state when not in use. For AMD CrossFire workloads, the driver will engage the non-primary GPUs to deliver full performance on-demand. The primary GPU can also enter the ZeroCore Power state during long idle as well. This delivers scalable benefits for the enthusiast. First, it effectively removes the power increase for users of AMD CrossFire under idle and light (single GPU) workloads. Second, it removes the noise penalty multiGPU users have always had to endure since the GPU fans are off in ZeroCore Power mode.

Packaging & Accessories

Our HD7790 sample hails from the premium brand GIGABYTE thus the packaging will be familiar to anyone who has recently purchased a graphics card from this company recently. The box is quite large for such a small card but it is neat, tidy and is clearly labelled. The two main features of this model that set it apart from the OEM versions are a slight increase in clockspeed to 1075MHz and a custom ‘Triangle cool’ heatsink.

Flipping the box over we find that GIGABYTE are keen to push their Triangle cooling design by showing a split diagram with directional arrows depicting the direction of airflow across the heatsink. Along with the 28nm process and PCI Express 3.0 compatibility (motherboard dependent) these features make up the mainstay of the card which are translated into the worlds 9 common languages.

The card is held fast in a foam brace and contained in a thick anti-static bag. The accessories are what we can only describe as sparse featuring just a driver CD, installation booklet and Molex to 6 pin power adaptor.

First Look

The GIGABYTE HD7790 has a very small foot print measuring just 190mm in length. The card is however a dual slot design thanks to the large, single fan cooler which dominates proceedings. The cooler looks strikingly similar (but slimmed down) to the Windforce range of coolers used on it’s higher end models. Hopefully this card will be just as quiet.

A nice touch was the protection afforded to the card in the form a little plastic tabs which slip over both the exposed gold fingers and various ports on the IO area.

GIGABYTE have stayed true to their trademark blue PCB colouration which may not appeal to all. While it is unobtrusive, we can’t help feeling a black PCB would appeal to a wider market however, GIGABYTE should be praised for daring to be different.

The IO area features both DVI-I and DVI-D ports along with HDMI and DisplayPort compatibility. Straddling these ports is a small, if somewhat useless vent given that the cooler is an open face design.

A single 6pin power port is to be found towards the end of the card which provides up to 75W of power. This however shouldn’t all be drawn from this port given that under normal gaming conditions the card will pull just 85W. GIGABYTE do however recommend a PSU capable of delivering 450W.

For those looking for a cheap upgrade path in the future, AMD and GIGABYTE have seen fit to add a Crossfire tab meaning this card can be linked up with another GPU from the same family to add some extra performance should you feel one card is not enough.

Let’s take a closer look at the card without the cooler…

Closer Look

the heatsink itself is fairly basic in design. Being simply a slab of aluminium with the additional benefit of triangle cooling – a small protrusion underneath the fan efficiently which directs airflow.

With the heatsink removed, we can see that there are 4×256 memory modules framing the Bonaire GPU. To the right is the VRM with a separate direct contact heatsink covering the MOSFETs.

The GIGABYTE HD7790 is a 5+1 phase power design utilising solid caps throughout.

The memory chips are produced by Hynix and carry a tag line of H5GQ2H24AFA R0C which is clocked to 6Gbps (effective).

Finally we arrive at the core of the card, codenamed Bonaire. The new core is built on the 28nm process and features 2.08 billion transistors. In addition to the extra transistors, steam processors and the increase in memory clockspeed over it’s brethren, the primitive clock rate has doubled to 2 prim / CLK. With these enhancements the new specifications state that this card in particular is capable of 60.2 G Texel/s texture fillrate along with a 17.2 GPixel/s Pixel fillrate. How this translates to real world performance we are about to find out…

Test Setup

With the latest Intel chipset release we decided to update our ageing X58 setup to the new X79 chipset. Not only that but we will be using the flagship Core i7-3960X Extreme Edition processor clocked to 4.5GHz to ensure we have no CPU bottlenecks. With 16GB of ram on board there should be minimal paging so the benchmarks we run today will hopefully give a true reflection of the graphics card’s performance.

Some of the components for our test bench were kindly donated by CORSAIR who provided the majority of components without whom we would not have been able to bring you this review so a big thanks to them.

Graphics cards on test:
GIGABYTE HD7790 1GB GDDR5

GIGABYTE GTX650 Ti 2GB GDDR5

AMD HD7770 1GB GDDR5
ZOTAC GTX660 2GB GDDR5
AMD HD7750 1GB GDDR5
MSI GTX560Ti-448 Twin Frozr III 1280MB GDDR5
MSI GTX560Ti-384 Twin Frozr III 2GB GDDR5

***NOTE*** Pre-release AMD Catalyst 13.3 beta drivers were used with the GIGABYTE HD7790 1GB GDDR5

Motherboard: MSI X79 Big Bang X-Power II
CPU: Intel Core i7-3960X Extreme Edition @ 4.5GHz
RAM – 16GB (4x4GB) Corsair Vengeance (Red) DDR3 @ 1866MHz 9-10-9-27
Power Supply – ANTEC High Current Pro 1200W
Hard Drive – Kingston HyperX 240GB
Cooler – Corsair H100

Benchmarks
Normally we would run the tests at four settings however at 2560×1600 both the GIGABYTE HD7790 and NVIDIA GTX650 Ti could not produce adequate (playable) frames per second at 2560×1600 so these tests were omitted as they served no purpose other than to state that 1920×1080 is the maximum resolution one could hope to utilise these two cards for.

Battlefield 3
Crysis Warhead
Metro 2033
Elder Scrolls: Skyrim
DiRT 3
Futuremark 3DMark 2011
Unigine: Heaven 2.5

Let’s see how today’s graphics card performed..

Temperature & Power Consumption

Power Consumption

To test for power consumption we do not use anything too technical, just a wall meter which measures the total system power draw minus the monitor.

Being that this card is slightly overclocked we expected a bigger increase in consumption than reported so this can only be good news for those looking to save a little cash on their electricity bills.

Temperature

To test temperatures we measured idle temperatures after booting windows, letting all applications finish loading and ran a few benchmarks. Once the benchmarks were complete we left the card to reach a cooling plateau where we then took the idle temperatures. For the load tests, we would normally run Furmark for 20 minutes, taking the absolute maximum temperature attained however we found that this throttled the card and resulted in spurious results. So we set Heaven running continuously for 20 minutes and used this as a temperature result as the card did not throttle with this application.

A great performance from such a small cooler. Surprisingly, the Triangle cooling design must be doing it’s job and not just a gimmick – that or the HD7790 is one cool customer. Obviously, in an enclosed case environment the temperatures above will doubtless increase but this is still a good result for the AMD card.

Acoustics
The card barely raised a murmur during testing even when placed under load. The large fan helps to keep noise levels down as it inevitably will spin much slower than a smaller fan to push the same amount of air. Couple this with the efficient cooling properties of the heatsink and then fan is allowed to spin even slower to keep temperatures under control which equates to less noise.

Battlefield 3

Battlefield 3 leaps ahead of its time with the power of Frostbite™ 2, the next instalment of DICE’s cutting-edge game engine. This state-of-the-art technology is the foundation on which Battlefield 3 is built, delivering enhanced visual quality, a grand sense of scale, massive destruction, dynamic audio and incredibly lifelike character animations. As bullets whiz by, walls crumble, and explosions throw you to the ground, the battlefield feels more alive and interactive than ever before. In Battlefield 3, players step into the role of the elite U.S. Marines where they will experience heart-pounding missions across diverse locations including Paris, Tehran and New York.

Average and minimum frames per second were measured using Fraps during the parking lot scene on Operation Sword Breaker. High and Ultra presets were loaded at both resolutions.

Crysis Warhead

Following the success of Crysis, the stand alone expansion “Warhead” was hotly anticipated to bring more game play, more weapons, improved visuals whilst maintaining better performance, the latter being what gamers wanted most. After all how many people upgraded their rigs just to play this game… In the game, you play as the upbeat Brit Sergeant “Psycho” Sykes, chasing down a Korean nuclear warhead. Throw in some ice shooting aliens and we’re bound to have a great game. It sure delivered.

Testing was done using Framebuffer’s Crysis Warhead benchmarking tool. The tests were configured to DirectX 10 at Enthusiast levels. Each test on the Ambush map was looped three times from which the average FPS was recorded.

The Elder Scrolls: Skyrim

Skyrim is not a direct successor to the very popular Oblivion. Instead it takes place 200 years after the events of Oblivion. The non-linear playing that made the Elder Scrolls such a popular series does however make a return along with the beautiful scenery the encompasses the world of Skyrim.

Average and minimum frames per second were measured using Fraps during the drop down passage to Riverwood. V-sync was disabled to allow fluctuating (higher the 60) FPS for these runs. It is however recommended that v-sync is left enabled during normal gameplay due to the games dynamics.

DiRT 3

As players race to elevate their global standing, DiRT 3 is back delivering mud, sweat and gears world over: from the intense weather-beaten rally stages of Europe, Africa and the US, to executing performance driving showcases and career challenges where car control is pushed to spectacular limits.

The in-game benchmarking tool was used to test performance. All the display settings were set to the maximum available and DirectX 11 was applied. The average FPS was recorded at the end.

Metro 2033

Based on the novel by the same name, Metro 2033 is a first person shooter with elements of survival horror. As Artyom, you trawl through the mutant infested metro systems of post-apocalyptic Moscow. The game delivers presents a grim ambience that reflects on the overall atmosphere of the underground setting. Metro 2033 uses the setting as a back drop to showcase some of the best visuals of any games out now, making it the ideal benchmark for those looking for the best graphics card.

The bundled benchmarking tool was used on Metro 2033, configuring the settings to High and making use of DirectX 11. The frontline scene was looped 3 times for each configuration. The average FPS was recorded at the end.

Futuremark 3DMark 11

3DMark 11 is the latest version of the world’s most popular benchmark. Designed to measure your PC’s gaming performance 3DMark 11 makes extensive use of all the new features in DirectX 11 including tessellation, compute shaders and multi-threading. The benchmark was run in both Performance and Extreme presets.

Unigine: Heaven 2.5

Heaven Benchmark is a DirectX 11 GPU benchmark based on advanced Unigine™ engine from Unigine Corp. It reveals the enchanting magic of floating islands with a tiny village hidden in the cloudy skies. Interactive mode provides emerging experience of exploring the intricate world of steampunk.

Conclusion

The AMD HD7790 (and in our case the overclocked GIGABYTE HD7790)shows us that you do not need to spend a massive amount of cash to gain playable framerates in the majority of today’s games at the most popular resolution. Costing almost a tenth of the price of the ridiculously expensive NVIDIA TITAN GPU yet churning out framerates at a much better ratio demonstrates where the smart money should go. We haven’t however reviewed the AMD HD7790 to compare against the flagship product from the opposition, the card the HD7790 is pitched against is the NVIDIA GTX650 Ti and to that end it triumphs.

Throughout the benchmarks, the AMD HD7790 outmanoeuvred it’s counterpart in the majority of tests which when you consider the HD7790 is 25% cheaper is a great victory indeed. Sure our sample has been breathed on by the overclockers at GIGABYTE but we doubt very much a reduction in clockspeed by 75MHz to the reference speed of 1GHz would make that much difference and to that end we are happy to conclude the HD7790 is the faster card out of the two as it currently lays. However…

£100 (estimated) is still not cheap. While it is on a par with the current HD7770 pricing and cheaper than the equivalent NVIDIA card it could easily be argued that the price is a fair one and we would agree. It cannot however be labelled a budget card and at this level of the market, cost is clearly a high priority. For occasional gaming this card will suit fine however for serious gaming, you will need to invest in a more powerful GPU to reap the benefits of quality settings and/or higher resolutions.

NVIDIA are also rumoured to be releasing a new competitor codenamed the GTX655 which is apt as it would settle between the GTX 650Ti and the GTX660 – right where the AMD HD7790 currently finds itself. How this new battle will pan out remains to be seen however for the moment, the HD7790 can hold it’s head aloft as the graphics card of choice at the entry level of the gaming market.

Pros:
+ Fair Price Point
+ DirectX 11
+ Very Quiet
+ Significantly faster than a HD7770

Cons:
– Struggles above 1920×1080 resolution
– Sparse Accessories